The prior art is familiar with arrangements in which a substantially constant-maximum-power-output solar array is matched to, for example, a jack pump through a battery, which charges and discharges to match the constant-output array to the device of fluctuating power requirements. It is also known in prior art, as in Kelley U.S. Pat. No. 3,917,213, to halve peak loads by counterbalancing, so that each complete cycle is characterized by two peaks of half of what would otherwise be the peak size.